Stability analysis and Heterotic studies in Maize Zea mays L inbreds for identification of elite hybrids with low phytic acid and high quality protein

Abstract

newlineMaize is an essential cereal crop after rice and wheat. It is predominantly used as food and feed by the world. Although it is considered to be a rich source of protein and minerals, the bioavailability of nutrients in maize diets is a crucial issue. This is mainly due to two major factors i.e., presence of phytic acid and lack of tryptophan. Hence, this study was determined to identify and select stable low phytic acid inbreds and elite tryptophan lines to develop hybrids with stable low phytic acid and high quality protein. For this, initially forty maize inbreds were screened across three locations with two replications. Twenty morphological and four biochemical traits viz., phytic acid, starch, free inorganic phosphorous and tryptophan were recorded. Four inbreds viz., UMI-467, LPA-2-395, LPA-2-285 and UMI-447 were stable for their low phytic acid content (2.51 mg/g to 3.47 mg/g) with a higher free inorganic phosphorous (1.78 mg/g to 1.87 mg/g). Following them, UMI-158, UMI-1099 and UMI-113 were moderately stable with a medium phytic acid content. These identified stable low phytic acid lines also were observed with negative pleiotropic effects such as reduced yield, lower starch content and poor seedling characteristics. Among the forty inbreds, DMR-QPM-04-05, DMR-QPM-01-06-02, DMR-QPM-03-72, DMR-QPM-06-12, DMR-QPM-09-13-1 and DMR-QPM-11-17 exhibited a higher and stable yield with higher tryptophan per cent (gt0.6 %) across locations. newlineAll the inbreds significantly varied for all the traits recorded across the locations with higher phenotypic and genotypic coefficient of variation. Higher PCV and GCV were found in seedling vigour index, phytic acid and free inorganic phosphorous. A high heritability coupled with genetic advance for the presence of additive gene action was observed in seedling vigour index, phytic acid, seed length and cob length. Therefore, these highly variable and heritable traits could be further improvised by effecting selection. The correlation of the traits revealed a positi